Electrode holder and guide for arc lamps



Sept. 17, 1940. D, Q MCCROSKEY 2,215,401

ELECTRODE HOLDER AND GUIDE FOR ARC LAMPS Filed DeC. ll, 1939 @brown/13d.

Patented Sept-.17, '19*40` j I y #UNITED STATES PATENT OFFICE ELECTRODE HOLDER AND GUIDE FOR ARC LAMPS David O. McCroskey, Portland, Oreg., assignor of one-half to Clarence W. Christenson, Portland, Oreg.

Application December 11, 1939, Serial No. 308,683

1 Claim. (Cl. 176-119) This invention relates to arc lamps and more similar to the jaws and feeding means embodied particularly to a support and guide for the elecin Patent No. 2,151,194- An electrode holder gentrodes or carbons. erally designated as II is engaged between the An object of this invention is to provide a twojaws I0 and comprises a stem or elongated supporting and guiding structure for carbon elecrod I2 which is preferably round in transverse 5 trodes which may be attached to lamp structures section and the outer end of the stem I2 is proat present in use which will permit the burning videdk with a head I4. The head I4 is conof a greater portion of the carbon than is at presstructed in the form of a socket provided with a ent possible, thus effecting not only a saving in bore I3 extending inwardly from the outer or carbon sticks but also in the time necessary to forward end thereof and the head I4 is provided 10 change carbons. A at diametrically opposite sides thereof with a Another object of this invention is to provide pair of longitudinally extending openings I5 an improved carbon holder which is so conwhich extend inwardly from the outer end and structed that the carbon will be firmly held thereterminate at their inner ends in a transversely inwith only a very short length of the carbon disposed cylindrical opening I6. This opening 15 projecting into the holder, so that the remain- I6 is substantially equal to the diameter of the ing portion may be used in the normal manner. bore I3. `Ihe openings I5 form a pair of clamp- A further object of this invention is to proing jaws Il and I8 between which the inner end vide an improved guide including a supporting of a carbon electrode I9 is adapted to engage. arm and a slidable guide member for supporting The inner terminal portion of the electrode I9 20 the carbon and theholder. Y is adapted to engage in the bore I3 and the elec- A still further object of this invention is to trode I9 is tightly held between the jaws I1 and provide, an improved carbon holder in the formV I8 by means of a jaw tensioning member 20. of an elongated bar or rod providedat one end The latter constitutes an abutment en'gageable thereof with a pair of resilient clamping jaws bythe inner end of the electrode I9 for limiting 25 which are arcuate in transverse section, the the extent of the insertion of the electrode I9 jaws tightly engaging about an end of the carbon into the holder. The jaw tensioning member 20 which projects only a very short distance incomprises a threaded member2l which engages wardly of the jaws, thus having all but about loosely through an opening 22 provided in the on'eeighth of an inch of the carbon for use in jaw Il and the jaw I8 is provided witha threaded 30 forming the desired electric arc. opening 23 within which the member 2| thread- To the foregoing objects and to others which ably engages. The outer end of the threaded may hereinafter appear, the invention consists member 2I is provided with a head 24 which is of the novel construction, combination and aradapted to engage against the outer side of the rangement of parts as will be more specifically jaw I'I and a handle or knob 25 is formed inte- 35 referred to and illustrated in the accompanying gral with the head 24 and provides a means drawing wherein is shown an embodiment of the whereby the tensioning member 20 may be roinvention, but it is to be understood, that tated to tension the two jaws I'I and I8. The changes, variations and modifications may be re- 'openings 22 and 23 are preferably positioned 40 sorted to which fall within the scope ofthe inforwardly of the transverse opening I6 so that 40 vention as claimed. the two jaws I1 and I8l can be readily moved.

In the drawing: toward each other in order to clamp the inner Figure 1 is a detail side elevation of a comend of the electrode I9 therebetween. The jaws binedr support, guide and holder for a carbon I'I and I8 are of transversely arcuate configuraelectrode associated T with feeding means of an tion and are formed of resilient material so that 45 arc lamp, when the tensioning member 20 is loosened the Figure 2 is a detail top plan of the supporting jaws I'I and I8 will open slightly in order to permeans, mit the removal or replacement of the electrode Figure 3 is a sectional view taken on line 3--3 therebetween. of Figure 1, and An electrode supporting bar generally desig- 50 Figure 4 is a fragmentary side elevation partly nated as 25 is positioned in substantially parallel in longitudinal section of the holder. relation to the holder Il and comprises an inner Referring to the drawing, the numeral I0 desbase part 2'Ifprovided with an opening 28 at its ignates generally a pair of clamping jaws which inner end through which an attaching bolt is are associated with an electrode feeding means adapted to engage for attaching the inner end of 55 the base member 2'I to the desired part ofthe lamp structure. In practice, the electrode feeding jaws I form part of an arc lamp structure associated with a motion picture projection ma-.

chine and the base bar 27 is adapted to bel secured to the desired portion of the projection machine.

An elongated guide bar 29 is formed integral with the base bar 27 and the guide bar 29 as shown in Figure 2 is substantially wider than the base -bar 21. The guide bar 29 is provided adjacent the inner end thereof` with an opening 39 which is parallel with the opening 28 and through which an attaching bolt is adapted to engage for mounting the supporting bar 28 in a substantially horizontal position and in parallel relation to the longitudinal axis of the holder II. A guide bar 29 is provided with an elongated slot 3| formed in the upper surface thereof and a second slot 32 is formed in the lower surface of the guide bar 29 and communicates with the lowerend of the slot 3l, thereby forming a substantially T-shaped guide slot extending lengthwise of the guide bar 29.

A slide member generally designated as 33 slidably engages in the two slots 3| and 32, and the slide 33 is provided with an upper part 34 slidably engaging in the slot 3I` and a lower part 35 slidably engaging in the lower slot 32. An upstanding electrode guide 39 extends upwardly from the upper surface of the guide bar 29 and is provided with a V-shaped electrode seat 31 within which the electrode I9 is adapted to looosely engage. A base plate 38 is formed integral with the guide 36 and extends at right angles relative thereto. The base plate 38 is substantially wider than the width of the slot 3i and slidably engages on the upper surface of the guide bar 29. The base plate 38 is secured by means of fastening devices 39 to the inverted T-shaped slide 33.

In the use and operation of the combined guide, support and holder, the head I4 of the holder II is adapted to initially receive the inner end of the electrode I9. The electrode may have only a very short portion thereof disposed between the jaws II and I8 and the projecting portion of the electrode I9 is adapted to engage in the V-shaped seat 37 of the slidable support or guide 36. The inner end of the stem I2 is clamped between the clamping jaws I0 forming part of the electrode feeding means. As the holder II with the electrode I9 is moved relative to an adjacent or confronting electrode I9a, the electrode I9 may slide relative to the guide 36 and this guide 33 may also slide lengthwise of the supporting bar 29. In this manner the electrode I9 will be maintained at all times in axial alignment with the electrode I9a.

A combined support and holder for an electrode constructed according to an embodiment of this invention will permit the use of a greater portion of the length of the carbon electrode than is at present possible, as the electrode I 9` may have only a very small portion of the length thereof engaged between the clamping jaws I1 and I 8. In practice, there need be only about one-eighth of an inch of the electrode I9 positioned between the jaws I'I and I8. By using the greater portion of the length of the electrode I9, there will be a considerable saving in time required to change the electrodes in addition to a material saving of the electrode itself.

With holders and feeding devices at present available, there is approximately two and onehalf inches of electrode which cannot be used due to the fact that the holder and guide means for the electrode will not permit the burning of the electrode for a shorter length.

The hereinbefore described guide and holder may be made in the form of an attachment for the present parts of an arc lamp structure, particularly an arc lamp structure associated with a motion picture projection machine.

What I claim is:

In a combined holder and guide structure for the carbon electrode of an arc lamp, the combination of an elongated supporting bar having its outer portion formed lengthwise thereof with an elongated slot `of inverted T-shaped cross section, an inverted T-shaped slide member positioned in said slot, a vertical guide having a V-shaped cutout adapted for receiving the electrode holder, a flat base plate mounted on the slotted outer portion of said bar and mer-ging at its forward end into the lower end of said guide, and means for connecting the base plate to said slide member whereby the guide will be connected to said bar.

DAVID C. MCCROSKEY. 

